| Effect of EMS on germination of einkorn wheat Taro FUJII National Institute of Genetics, Misima, Japan Very high mutagenic effects of ethyl methane sulphonate (EMS) were already reported by many researchers. Normal seeds, and heterozygotic seeds from the cross between chlorina and normal green in Triticum monococcum flavescens were used in this experiment. The aim of this experiment was to determine the differences in mutagenic effect for a specific gene and the difference in the appearance of mass mutation between gamma ray and EMS treatments. For two hours steeped seeds were treated with 0.1, 0.3 and 0.5% EMS solutions for 22 hours. For comparison, for 24 hours steeped seeds were subjected to 0.5, 1.0, and 1.5 kr of gamma-rays. Moreover, EMS and gamma-ray treatments were combined to examine the synergistic effect of both treatments. The treatments were so combined that 2 hours steeped seeds were placed in EMS solution for 22 hours and gamma-ray exposure was done after 5 min. washing with tap water. Steeping and EMS treatments were done under room condition at 20C. gamma-rays had almost no effect on germination rate of the normal strain, but the F1 hybrids were affected. In EMS treatments, germination rate in both strains decreased with increasing concentration of EMS, more markedly in the F1 lot, as shown in Table 1. (Of course, germination rate of F1 seeds was a little inferior to that of the normals because they are usually smaller than normal seeds). Moreover, combination of EMS and gamma-ray treatments showed severer killing effect than each single treatment; about 50% and only 14% seeds germinated in the normal and the F1 batch, respectively, in the EMS 0.5% and gamma-ray 1 kr treatment lot. Almost all seedlings died out in these lots. Additive or synergistic effects of both treatment are assumed. The appearance of chlorina stripes due to somatic mutation is now under examination. |